These are probably the most familiar types of publications for the general audience. The news magazines, websites, blogs and related types of publications provide access to hundreds of thousands of reports on an unimaginable number of topics and issues. No competent information strategy can ignore these types of publications. So for your information task about football player head injuries, reports published in journalistic sources would be widely available.
Journalistic sources also produce publications for their advertisers. Media kits, promotional documents and advertising rate sheets help advertisers decide whether they should place an ad in a particular journalistic publication or on its website or mobile publication. These are considered business-to-business publications and are not widely available to the general public the way the media organization’s news reports are. They would also fall into the category of “private sector” contributed information since the purpose is promotion of the business rather than the journalistic mission that news stories have.